Modeling lacaziosis lesion progression in common bottlenose dolphins Tursiops truncatus using  long-term photographic records

Abstract

Lacaziosis (lobomycosis) is a skin disease caused by Lacazia loboi, occurring naturally only in humans and dolphins. Attempts to culture the pathogen in vitro have been unsuccessful, and inoculation studies of lacaziosis development in mice have provided only limited, short-term data on the progression and propagation of L. loboi. The present study used photographic data from longterm photo-identification and health assessment projects to model and quantify the progression of lacaziosis lesions in 3 common bottlenose dolphins Tursiops truncatus from Sarasota Bay, Florida, USA. Dorsal fin images throughout each animal's sighting history were examined for lesion growth, and the proportion of lesion coverage in each photograph was estimated using image analysis tools in Adobe Photoshop ® . The progression of lacaziosis lesions and lesion growth rates were modeled using a non-linear monomolecular growth model. As data on lacaziosis development and advancement are limited in humans and laboratory animals, dolphins with a long-term case history of the disease may serve as a good animal model to better understand lacaziosis progression. Furthermore, this study demonstrates the utility of long-term population monitoring data for tracking the progression of a poorly understood disease that is relevant to both dolphin and human health. KEY WORDS: Lacaziosis · Lacazia loboi · Bottlenose dolphin · Monomolecular growth model · Skin disease · Sarasota Bay · Lobomycosis Resale or republication not permitted without written consent of the publisherDis Aquat Org 90: [105][106][107][108][109][110][111][112] 2010 gest that the disease is likely endemic to the bottlenose dolphin communities on the east coast of Florida (Caldwell et al. 1975, Murdoch et al. 2008.In vitro attempts to culture the lacaziosis pathogen have not been successful. As a result, very little is understood about the conditions under which the pathogen grows and thrives, as well as its source and transmission route (Wiersema & Niemel 1965, Pang et al. 2004, Lupi et al. 2005, Paniz-Mondolfi et al. 2007). Experimental inoculation attempts have been made using guinea pigs (Wiersema & Niemel 1965), hamsters (Wiersema & Niemel 1965, Opromolla & Noguiera 2000, tortoises (Geochelone denticulate, G. carbonaria and Kinosternon scorpioides; Sampaio et al. 1971), monkeys (Macacca mulatta, M. nemestrina and M. fascicularis; Caldwell et al. 1975), armadillos Euphractus sexcinctus (Sampaio & Braga-Dias 1977) and mice (Wiersema & Niemel 1965, Caldwell et al. 1975, Opromolla et al. 1999, Madeira et al. 2000, 2003, Belone et al. 2003, but many of those attempts yielded only short-term data on the development of the disease. Opromolla et al. (1999) were able to successfully inoculate a Swiss strain of mice with lacaziosis and follow disease progression up to 18 mo post-inoculation; however, clinical presentation of the disease did not occur, and very few fungal cells were active by the end of the study. Other studies have demonstrated that BALB/c mice may be a suit...

Abundance Estimate of Bottlenose Dolphins (Tursiops truncatus) in the Lower River Shannon candidate Special Area of Conservation, Ireland

“…Photo-ID has also been used to study a wide range of marine mammals, including other dolphin species, baleen whales (Hammond, 1986), and seals (Hiby et al, 2007), as well as terrestrial animals. In addition to abundance, the technique is used to estimate movements, population parameters, and behavioural ecology (Wood, 1998;Wilson et al, 1999;Grellier et al, 2003;Weir et al, 2008;Hart et al, 2010).…”

An assessment of the natural marking patterns used for photo-identification of common minke whales and white-beaked dolphins in Icelandic waters

“…Mitchell, 1970; Tsutsui et al ., 2001; Arnold et al ., 2005; Rosso et al ., 2008; Keener et al ., 2011; Lodi & Borobia, 2013) and to monitor the development of diseases in free-ranging whales and dolphins (e.g. Van Bressem et al ., 2003; Burdett Hart et al ., 2010; Maldini et al ., 2010). However, the use of natural marks to identify cetaceans has certain limitations (summarized in Hammond, 1986, 1990).…”

Skin Lesions on Common Bottlenose Dolphins (Tursiops truncatus) from Three Sites in the Northwest Atlantic, USA

“…[2], [3], [6], [8], [10]–[12]), producing minimum disease prevalence estimates [11] as the detection of lesions are restricted to body parts that are routinely photographed. Although limited for determining skin disease causes, photo-id data provide a relatively inexpensive and non-invasive means of assessing body and skin condition [13], as well as lesion progression, recurrence, or resolution [9], [14], [15] for free-ranging marine mammal populations. Other studies have relied on by-catch or stranding data [1], [4], [5], [9], [16], [17], or capture-release health assessment data [3], [18], [19] to estimate disease burden in wild populations; however, these methods can be limited by small sample sizes or in the case of stranding data, biased towards individuals with compromised health [20].…”